Wheel-type excavating machine for hard materials

ABSTRACT

An excavating machine of the type including a chassis and a digging unit mounted for digging movement thereon. The unit comprising an endless wheellike member and a plurality of peripherally spaced sets of laterally staggered tooth members detachably mounted in angularly oriented relation on the wheellike member for moving excavated material upwardly and outwardly of the digging unit. The body of each tooth member having leading and trailing ends and inner and outer edges extending therebetween, and including an attachment portion adjacent the leading and trailing ends, and a blade portion made integral therewith adjacent the leading end and outer edge thereof. A plow assembly is mounted for selective directional adjustment on the chassis and includes an angularly oriented winglike scraper construction operative on opposed sides of the digging unit for moving excavated material away from the digging unit.

United States Patent [72] Inventors VincentS.Penote Shaker Heights; Melvin K. Rear, Chesterland, both of Ohio [21] Appl. No. 783,244 22 Filed Dec. 12,1968 [45] Patented Oct. 5, 1971 [73] Assignee The Cleveland Trencher Company Cleveland, Ohio [54] WHEEL-TYPE EXCAVATING MACHINE FOR HARD MATERIALS 12 Claims, 15 Drawing Figs. [52] US. Cl 299/25, 299/84, 299/93, 37/94, 37/142 R, 37/189 [51] Int. Cl E02f 5/08 [50] Field of Search 37/94-97, 142,191A, 189,192 A; 299/39, 84, 91, 93, 25; 175/383,4l2; 172/713; 143/141-146, 133, 135

[56] References Cited UNITED STATES PATENTS 2,191,958 2/1940 Greiner 299/93 X 2,284,178 5/1942 Sublett 37/142 UX 2,336,487 12/1943 Lewis et al.. 37/94 UX 2,637,917 5/1953 Klaucke 37/142 X 2,666,273 l/l954 Mclninch 37/142 X 2,950,096 8/1960 Krekeler et a1. 175/383 X I4 O 5} p w V l2 1 8 33 (K 32 L HI 3 l I I Q 1 i i no u 0 fl Primary ExaminerRobert E. Pulfrey Assistant Examiner-Clifford D. Crowdler AttorneyTeare, Teare & Sammon ABSTRACT: An excavating machine of the type including a chassis and a digging unit mounted for digging movement thereon. The unit comprising an endless wheellike member and a plurality of peripherally spacedl sets of laterally staggered tooth members detachably mounted in angularly oriented relation on the wheellike member for moving excavated material upwardly and outwardly of the digging unit. The body of each tooth member having leading and trailing ends and inner and outer edges extending therebetween, and including an attachment portion adjacent the leading and trailing ends, and a blade portion made integral therewith adjacent the leading end and outer edge thereof. A plow assembly is mounted for selective directional adjustment on the chassis and includes an angularly oriented winglike scraper construction operative on opposed sides of the digging unit for moving excavated material away from the digging unit.

Pmmm 5|97l 3,610,691

" sum 2 0F 4 INVENTORS VINCENT s. PENOTE MELVIN K. REAR BY PATENTED mm 5 IHYI SHEET 3 BF 4 FIGJO INVENTORS VINCENT s. PENOTE MELVIN K. REAR BY ATTORNEYS PATENTEI] HUT 5197i 3,610,691

VINCENT S. PENOTE MELVIN K. REAR rm 7M ATTORNEYS WHEEL-TYPE EXCAVATING MACHINE FOR I-IARD MATERIALS BACKGROUND OF THE INVENTION This invention relates to excavating machines, and more particularly to excavating machines which are adapted for digging in hard terrain, such as frozen ground, coral or the like.

In recent years, the extremely rapid development of the generally tropical areas of the world have resulted in an acute need for excavating machines which are capable of digging in hard ground, such as coral. In addition, there have been attempts to extend the construction season in those regions which are subjected to freezing temperatures, which has also required a need for trenching apparatus which is capable of digging in frozen ground or the like. Such requirements have presented at least a twofold problem. First, the excavating machine must be capable of cutting through the hard soil materials; and secondly, the machine must be capable of expeditiously removing such materials from the trench which has been excavated. Recently, a number of attempts have been made to provide an excavating machine which is capable of digging in such hard terrain, but such efforts have not been satisfactory for various reasons. For instance, present machinery has not been capable of extended operation without frequent maintenance. In addition, these machines have not provided for the expeditious and efficient removal of the excavated material which has resulted in considerable loss of time and effort during the digging operations.

One of the major maintenance problems encountered relates to the digger teeth which are provided adjacent the periphery of the digging wheel for cutting through the material to be excavated. I-Ieretofore, the teeth and their mountings were readily damaged or worn, thereby reducing the effective working time of the excavating machine and, hence, contributing substantially to the overall costs of the excavating operation. In addition, previous arrangements for mounting the teeth impeded the movement of the digging wheel so as to reduce the efficiency of the excavating operation. Moreover, conventional bucketor ladder-type excavating equipment has not been effective in digging such hard or high density materials, particularly when required to dig relatively narrow and/or deep trenches, such as for utility lines or other similar installations.

SUMMARY OF THE INVENTION An excavating machine of the type having a chassis and a digging unit mounted on the chassis for digging movement and with the machine comprising, an endless digging unit including a rimlike wheel member pivotally mounted on the chassis and supporting a plurality of peripherally spaced sets of laterally staggered tooth members disposed in angular and offset relation with respect to one another for moving excavated material upwardly and outwardly from the digging unit upon forward movement of the machine. The body of each tooth member having leading and trailing ends and inner and outer edges extending between said ends, and including an attachment portion adjacent the leading and trailing ends, and a blade portion integral with the attachment portion adjacent the said leading end and outer edge thereof.

A plow assembly may be mounted for selectively adjustable sliding movement on the machine chassis and includes an angularly oriented winglike scraper construction operative on opposed sides of the wheel member for moving the excavating material away from the digging unit upon forward movement of the machine.

By the foregoing arrangement, there is provided a simple, yet rugged construction for a high inertia digging unit which imparts high load impact forces on the material to be excavated and which can be rapidly operated for relatively high speed digging operations without detrimental wear and/or damage to the component parts thereof. The unit includes a sequential and relatively high-density digger tooth arrangement having a plurality of sets of digger tooth members disposed in a predetermined angularly oriented and patterned relation for imparting a substantially continuous sawlike cutting action on the material to be excavated. Such cutting action is particularly efficient for cutting through hard, highdensity, frozen or other such materials with a minimum of time and effort, especially when excavating relatively narrow and/or deep trenches or the like.

The invention further incorporates a novel construction for a plowlike mechanism adapted for detachable mounting and selective longitudinal shifting adjustment on the machine chassis for moving material or soil from the digging unit of the machine. Such mechanism is of a relatively lightweight, compact construction, which can be quickly and easily actuated by the operator, and which requires minimum maintenance resulting in reduced expense during use thereof. In addition, the toothed digger unit and plow mechanism of the invention can be employed with present and/or new excavating machines with a minimum of cost and/or change thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of one form of an excavating machine embodying the digging unit and plow mechanism of the present invention;

FIG. 2 is an enlarged fragmentary plan view of a portion of the digging unit of the present invention;

FIG. 3 is an enlarged section view taken along the line 3-3 of FIG. 1;

FIG. 4 is an enlarged front elevation of one of the digger tooth members removed from the assembly of FIG. 1;

FIG. 5 is a side elevation of a blank for one of the digger tooth members removed from the assembly of FIG. I;

FIG. 6 is a bottom view of the digger tooth member blank of FIG. 5 looking in the direction of line 6-6 of FIG. 5;

FIG. 7 is a side elevation view of a digger tooth member showing the opposite side from that of FIG. 5;

FIG. 8 is a bottom view of the digger tooth member looking in the direction of line 88 of FIG. 7;

FIG. 9 is an enlarged side elevation view of one of the mounting bracket members for a digger tooth member removed from the assembly of FIG. 1;

FIG. 10 is an end view of the mounting bracket member of FIG. 9;

FIG. ll is a top plan view of the mounting bracket member ofFIG. 9 looking in the direction of line 11-11 of FIG. 9;

FIG. 12 is an enlarged side elevation view partially broken away, of the plow mechanism of the invention removed from the assembly of FIG. 1;

FIG. 13 is a top plan view, partially broken away, of the plow mechanism of FIG. 12, and showing a portion of the digging unit in broken lines;

FIG. 14 is an enlarged fragmentary section view taken along line 14-44 ofFIG. l2; and

FIG. 15 is an enlarged fragmentary top plan view of a bracket and tooth member mounted on a portion of the support rim of the digging unit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring again to the drawings and in particular to FIG. I, there is illustrated generally at 10, one type of excavating machine with which the present invention may be employed. As shown, the machine 10 may include an endless digging unit, illustrated generally at 14, on which a plurality of digger tooth members, such as at 12, may be mounted in predetermined staggered relation. The unit 14 shown may be adapted for rotational movement (indicated by the arrow 16) about a horizontal axis; and may move transversely (indicated by the arrow 18). Though the digger tooth members 12 are illus trated for use with an endless wheellike digging unit, it is to be understood that they may be employed with other types of excavating equipment, such as ladder-type diggers, back hoes or the like, as desired.

In the preferred form, the digging unit 14 (FIG. 1) comprises a generally circular, digging wheel member 20 having a generally solid outer ring 22 and an inner ring 24 of substantially reduced thickness compared to that of the ring 22. The inner ring 24 may be provided with teeth 26 projecting outwardly from the opposite sides thereof for engagement with a sprocket member 28 for imparting driving movement to the wheel 20. The sprocket 28 may be drivingly connected in any suitable manner, such as by a chain 30, to a drive sprocket 32, which in turn may be drivingly connected to a suitable drive mechanism (not shown) associated with the excavating machine 10. The wheel member 20 may be mounted on the excavating machine 10 in any suitable manner, such as by support drums 34a-c, which may be supported for rotation on a boom member 35. The boom member 35 is preferably pivotally connected, as at 33, at one end to the excavating machine to move the digging wheel upwardly and downwardly in a generally vertical plane.

In general, each of the digger tooth members 12 comprises an attachment means 36 (FIG. 3) which is adapted for attachment to a bracketlike support member 38, and a blade 40 made integral with the attachment means 36 which extends generally radially away from the outer ring 22 in the installed position thereof. As shown, the blade 40 is preferably concavo-convex in configuration and is angularly disposed at a predetermined angle a such as 10, with respect to the direction of digging movement, as indicated by the arrow 42. By the foregoing arrangement, the material being dug will tend to be directed generally forwardly in the direction of digging movement. A plurality of the tooth members 12 may be disposed in predetermined staggered relation (FIGS. 1 and 2) along the periphery of the outer ring 22 so that the material being dug will be continuously directed toward the center of the outer ring 22 in such a manner to provide for moving the excavated spoil forwardly, upwardly and out of the trench T.

A plow assembly 41 is preferably mounted on the chassis for directing the excavated material removed from the trench T outwardly away from the digging unit 14. A crumber shoe 43 may be attached adjacent the end of the boom 35 adapted to scrape the bottom of the excavation and push any loose material forwardly into the path of the tooth members 12 in a manner which is more fully described in the copending application of Vincent S. Penote and Melvin K. Rear, Ser. No. 776,892 filed Nov. 19, 1968.

Referring now to FIGS. 9, l and 11, each of the digger tooth members 12 may be adapted for attachment to the digging wheel 20 in any suitable manner, but are preferably attached thereto by means of the bracketlike support members 38. Each support member 38 may include a generally L- shaped body 39 (FIG. having a flangelike base portion 44 adapted for attachment to the digging wheel 20, such as by welding or the like, and an upright flange portion 45 which extends generally perpendicularly with respect to the base portion 44. As mounted, the base portion 44 is disposed generally horizontally and parallel to the outer surface of the digging wheel while the upright portion 45 projects radially outwardly therefrom adapted for connection to a respective digger tooth 12. The upright portion 45 may be provided with a generally planar front face 46 which extends generally parallel to the direction of digging movement when in the installed position. Each base portion 44 may be provided with a top face 51 which extends generally perpendicular to the front face 46 to provide a bearing surface for the tooth member in a manner to be more fully described hereinafter. As shown in FIG. 9, the opposite ends 48 and 50 of the support member 38 are preferably inclined with respect to one another to provide relatively sharp cutting edges, such as at 47 and 49, adjacent the opposed ends to offer less resistance to movement of the support member through the material being excavated. The inclination of the surfaces 48 and 50 is preferably dual directional by first being inclined toward one another in a direction from the top surface 52 adjacent the upright portion 45 toward the bottom surface 54 adjacent the upright portion 45 toward the bottom surface 54 adjacent the base portion 44, and then being inclined toward one another in a direction from the front surface 56 adjacent the base portion 44 toward the back surface 58 which extends between the top and bottom surfaces 52 and 54, respectively. By this arrangement either end of the support member 38 may be used as the leading end so that the support member may be effectively reversed for proper positioning of the digger tooth members 12 on the digging wheel.

The digger tooth 12 is preferably formed from an originally flat, elongated unitary piece or blank 60 (FIG. 5) which may be made of steel or the like. The blank 60 may be of substantially uniform thickness (FIG. 6) having substantially planar, parallel surfaces 62 and 64. As the surface 62 will engage the material to be excavated, such surface 62 will be referred to as the front surface and surface 64 will be referred to as the back surface. Preferably, the general planes of the front 62 and back 64 surfaces are generally vertically disposed when in the installed position (FIG. 3).

In the preferred form, the blank 60 comprises a body 61 which is generally trapezoidal in configuration (FIG. 5), defined along one side by a longitudinally extending planar inner edge surface which as adapted to be disposed adjacent the digging wheel 20, and which extends lengthwise generally in the direction of digging movement. The trailing end of the blank 60 is defined by a generally planar trailing edge surface 82 which commences adjacent the inner edge surface 80 and which extends generally linearly and angularly forwardly with respect thereto in the direction of digging movement, such as at an angle b of 15 plus or minus 1, terminating in a generally planar outer edge surface 84 which is disposed generally angularly with respect to the inner edge surface 80. The leading end of the blank 60 is preferably beveled lengthwise (FIG. 6) thereof to form an inclined surface 86 which extends between and terminates at its opposed extremities in the inner edge surface 80 and the outer edge surface 84. As shown, the inclined surface 86 commences along a common edge 88 formed by the intersection of the inclined surface 86 and the front surface 62, and then extends angularly forwardly, such as at an angle c of 45, terminating in the back surface 64 to fonn a cutting edge 89 adjacent the leading end of the tooth member 12. Preferably, the cutting edge 89 extends generally radially outwardly from the outer ring 22 when the tooth member is in the installed position, and angularly forwardly in a direction away from the inner edge surface for effective cutting action through the material to be excavated.

The digger tooth 12 formed from the blank 60 may be attached to the support member 38 in any suitable manner, but preferably includes an attachment means 36 in the fonn of a generally flat shank 70 which is defined by substantially parallel surface portions 72 and 74 (FIG. 8) which extend lengthwise along the side of the tooth 12 adjacent the inner edge surface 80. The surface portions 72 and 74 extend generally parallel to the direction of digging movement merging smoothly with the blade portion 40 adjacent the outer edge surface 84 and leading end of the tooth member 12. As seen in FIGS. 4 and 10, the surface portion 72 and inner edge surface 80 may be disposed in confronting bearing engagement with the front face 46 and top face 51, respectively, of the support member 38 in the installed position thereof. The shank 70 may also be beveled, as at 53, between the surface portion 72 and inner edge surface 80 to assure firm contact of such surfaces. The shank 70 (FIG. 7) may be provided with a plurality of apertures, as at 76, which are adapted for alignment with apertures, as at 78, provided in the bracket member 38 (FIG. 9) and through which suitable fasteners 79, such as bolts or the like may be inserted (FIGS. 3 and 15) to secure the digger tooth 12 to the upright portion 45 of the respective bracket member 38.

The blade portion 40 extends generally longitudinally of and radially outwardly from the digging wheel 20 and is preferably generally triangular in configuration. As shown, the

apex of the triangle (FIG. 7) is disposed adjacent the outermost extremity of the trailing edge surface 82 at the juncture, as at 90, of the trailing edge surface 82 and the outer edge surface 84. The blade is preferably troughlike in configuration, including a concavely curved inner directing surface 92 and a convexly curved back surface portion 93. As the blade is made from a generally flat blank, the back surface portion 93 will generally conform to the contour of the directing surface 92. By this construction, a plane passing through and normal to the front 62 and back 64 surfaces will define a pair of lines therealong which will. be generally parallel to one another. The directing surface 92 preferably merges smoothly with the inner surface portion 72 of the shank 70 to form a rounded shoulder 94 which is defined by a radius of curvature which increases generally linearly from the juncture 90 to the common edge 88. As the inclined surface 86 is disposed along the full length of the leading end of the tooth, the respective portions of the inclined surface 86 adjacent the leading end of the blade 40 and shank 70 will also merge smoothly with one another to form a continuation of the rounded shoulder 94 having a radius of curvature which also increases generally linearly from the common edge 88 to the cutting edge 89.

Preferably, the curvature of the directing surface 92 is such that the concave troughlike depression formed thereby extends generally longitudinally of the blade portion 40 with its radius of curvature increasing generally linearly from the juncture 90 to the common edge 88, and then, at a greater linear rate along the inclined surface 86 from the common edge 88 to the cutting edge 89. Preferably, the axis XX of the radius of curvature extends generally parallel to the inner surface portion 72 of the shank 70 and angularly outwardly, such as at an angle d of 11, with respect to the inner edge surface 80. Preferably, the linear rate of increase of the radius of curvature is such that the outer edge surface 84 extends angularly outwardly away from the inner edge surface 80 in a direction away from the juncture 90 and the linear edge 96, defined by the directing surface 92 and the outer edge surface 84, will be disposed at an acute angle e, such as 9 with respect to the general plane of the inner surface portion 72 of the shank 70. By this arrangement, the leading edge 89 is approximately twice the length of the trailing edge surface 82, and the blade portion 40 of the tooth will be angularly opened to the direction of digging movement so that the material excavated will be directed toward the center of the trench being dug and also radially outwardly in a direction toward the adjacent face of the outer rim 22 of the digging wheel 20.

As can be seen in FIG. 15, in the mounted position the inclined surface 86a adjacent the shank 70a is slightly obliquely disposed with the adjacent inclined end surface, such as 50a, of the support member 38a, thereby providing a smooth, generally continuous surface adjacent the leading end of the tooth member 12 and support member 38 to facilitate the cutting action of the combined unit through the material to be excavated.

Referring now to FIGS. 1, 2 and 15, to provide an efficient and effective digging action, a series of tooth members l2a-f may be positioned in a predetermined spaced relation about the periphery of the digging wheel 20. This arrangement pro vides a sequential sawlike digging action which preferably begins with a narrow cut substantially aligned with the center of the digging wheel 20, and which gradually increases in width outwardly toward the opposed sides 98 and 99 (FIG. 3) of the digging wheel as the excavating machine advances forwardly. In the preferred form, four sets of sequentially arranged blades are provided on the digging wheel, that. is, the sequential arrangement of the blades is repeated in each quadrant of the wheel, and as shown, tooth members 1211-) represent one series and tooth member 12a the first tooth of the next series.

As shown in FIGS. l and 2, a plurality of support members 38a-f are mounted in spaced relation along the outer surface of the outer ring 22 of the digging wheel 29 and are preferably disposed at 15 intervals thereon. In this instance, each quadrant of the wheel may be provided with six support members with the respective base portions 44afof each one of each pair alternately projecting in an opposite direction from one another. As shown in FIG. 2, the leading support member, such as 38a, in each set is positioned with the front face 46a of the flange portion 45a disposed in approximately centered relation between the opposed sides 98 and 99 of the wheel 14. In this position, the portion of the cutting edge 86a adjacent the shank 70a of the associated tooth I20 is slightly offset with respect to the sides 98 and 99, and the directing surface 92a is disposed angularly outwardly toward the side 98. The next support member 38b is positioned so as to face in the opposite direction from the first member 38a, and is also preferably positioned so that the portion of the cutting edge 86b of the tooth 12b is slightly offset in the opposite direction with respect to the opposed sides of the wheel. By this arrangement, the first pair of blades will cut a narrow path through the material to be excavated. A second pair of blades 12c and 12d may be mounted on oppositely disposed support members 380 and 38d to provide a medium width cut. Preferably, the members 38c and 38d are positioned on the wheel 14 so that the directing surfaces 92c and d are disposed angularly inwardly to direct material outwardly toward the opposed sides 98 and 99, and the cutting edges 89(: and 89d adjacent the shanks 70c and 70d of the teeth 12c and 12d are disposed midway between the center of the wheel and the sides 98 and 99, respectively, to provide a wider out than that made by the previous pair of blades 12a and 12b. A third pair of oppositely disposed support members 38e and 38f are positioned with their front faces 46c and f disposed intermediate the opposed sides 98 and 99 and generally aligned in the direction of digging movement of the front faces 46c and 46d of the support members 380 and 38d, respectively, having the associated blades 12c and 12f mounted thereon. Preferably, the support members 38c and f are disposed in reverse direction to the support members 38c and d, respectively, so that the cutting edges 89: and 89f ad jacent the shanks 70c and f are positioned outwardly of the cutting edges 89c and 89d, respectively. ln addition, the

directing surfaces 92c and f open toward one another and are disposed angularly outwardly toward the opposed sides 98 and 99, respectively, having the portions of the cutting edges 86c and 86f adjacent the outer edge surface 84c and f radially aligned therewith to provide a still wider out which is substan tially equal to the transverse width of the outer rim 22 of the wheel 14. As can be seen, a progressively widening path will be cut through the material to be excavated as the digging wheel is rotated in a generally vertical plane with'such cutting action being repeated four times for each complete revolution of the wheel.

Preferably, the outer rim 22 is made of solid construction to increase the inertia of the digging wheel to maintain a substantially uniform speed of rotation and greater impact force to enable the tooth members l2 to more readily cut through hard materials. Preferably, the moment inertia is in the range between about 50,000 to 75,000 pound-feet squared. In addition, the digging wheel is rotated at speeds greater than conventional speeds, and preferably twice as great, such as approximately 19 rpm. to achieve a sawlike action for maximum digging efficiency and removal of material from the trench.

it has been found that with the construction of the support and tooth members of the invention, and the sequential and angularly oriented disposition of the tooth member on the digging wheel that there is provided a digging unit which is extremely well suited for digging hard materials, such as frozen ground, coral or the like, and which digging is achieved more effectively and efficiently than with previously known digging units.

In the preferred form, the plow assembly or mechanism 41 (FIGS. 12-14 comprises a support member 102 which is adapted for attachment at one end to the machine chassis and at the other end adapted to support a plowlike subassembly 104 which acts to divert or push the material thrown up and out of the excavation by the tooth members 12 outwardly away from the excavation.

Preferably, the support member 102 is generally U-shaped in configuration (FIG. 13) and includes a pair of laterally extending, generally parallel arm members 106 and 108 which may be connected at one end adjacent the opposed distal ends of a generally perpendicularly extending crossbar member 110, by weldments or the like. Preferably, the arms 106 and 108 project rearwardly away from the chassis a sufficient distance so as to extend laterally and parallel with respect to the opposite sides of the digging wheel 14. The crossbar member 110 may be provided with L-shaped flange members 111 and 113 adjacent the opposed distal ends thereof which extend forwardly of the crossbar and are provided with axially aligned apertures, such as 117. Apertures 117 are adapted to loosely receive suitable connectors, such as pins or the like (not shown), to provide a pivotal connection for the support member 102 with the machine chassis to enable the arm members'106 and 108 to be moved from a generally horizontal operative position to a raised nonoperative position, as indicated by the phantom lines 115 of FIG. 1.

The arm members 106 and 108 may be of any suitable configuration, but preferably are of generally I-shaped configuration (FIG. 14). As shown, each member may include a generally vertically extending web portion 116 having generally horizontally extending flanges, as at 118 and 120, adjacent its upper and lower ends, for slidably supporting the plowlike subassembly 104 thereon.

In the preferred form, the assembly 104 is generally V- shaped in configuration (FIG. 13) and may include a pair of spaced, oppositely disposed bamelike scraper members, such as 122 and 124, adapted for sliding movement lengthwise with respect to the arm members 106 and 108. As shown, each of the scraper members 122 and 124 may be angularly disposed relative to each of the respective arm members 106 and 108, and may be inclined toward one another in a direction of digging movement, as indicated by arrow 112 of FIG. 13. Preferably the leading ends of the scrapers are spaced apart from one another with the minimum transverse distance therebetween being greater than the maximum transverse width of the digging wheel 14 to enable the digging wheel to be rotated freely within the space therebetween. By this arrangement, the material being removed from the excavation and thrown up and forwardly of the plow subassembly will be diverted or directed by the scraper members 122 and 124 outwardly away from the excavation as the digging wheel 14 moves forwardly.

The scraper members 122 and 124 are substantially identical to one another, and therefore, for purposes of illustration only one, such as 124, will be described in detail herein and like parts are designated with like reference numerals. The scraper 124 may be of any suitable configuration, such as polygonal (FIG. 12) and comprises a generally flat plate member 130 having a linearly extending lower marginal edge 133 which is provided with a flange 134. A guide plate 132 may be provided adjacent the leading end of the plate 130 and may extend generally parallel to the direction of digging movement of the excavating machine. A flange 136 may also be provided along the lower marginal edge of the guide plate 132 which may be made integral with the flange 134 adjacent the leading end thereof, and may extend angularly upwardly and forwardly to provide the skilike slide surface along the lower edge of the scraper member 124 to facilitate sliding movement along the ground.

To achieve sliding movement of the scraper member 124 with respect to the arm 108, the plate 130 may be provided with an opening 140 intermediate the leading and trailing ends thereof which is adapted to receive the free end of the arm 108 therethrough. Preferably, the opening 140 is generally shaped in configuration (PS6. 14) having upper 142, intermediate 144 and lower M6 enlarged slots which are adapted to slidably receive the upper flange 118, web 116 and lower flange 120 of the arm member 108 therein, respectively.

The plow subassembly 104 may be provided with a means to guide and facilitate sliding movement of the scraper members 122 and 124 along the respective arms 106 and 108. In the form shown, each of the scraper members 122 and 124 may be provided with guide members, such as 123 and 125, respectively, which may be carried by the scraper members. The guide members 123 and 125 are generally of identical construction so that only one, such as 125, will be described in detail with like parts designated by similar reference numerals. Preferably, the guide member 125 is of a polygonal configuration, such as rectangular (FIG. 13), and is adapted to be disposed within one of the slots, such as 142, defined by the respective opening 140. The guide members 125 may be secured to the respective scraper'member 124 in any suitable manner, such as by welding or the like, having its lengthwise axis extending generally parallel to the lengthwise axis of the arms 106 and 108 and angularly with respect to the general plane of the upright plate member of the scraper member 124. As shown in FIG. 14, the guide member 125 may include a pair of laterally extending oppositely disposed bearing members and 152, such as generally L-shaped angle iron bars. Preferably, the members 150 and 152 are disposed in opposed relation with respect to one another and having upright flanges 156 and 158 and generally horizontally extending flanges and 162 which extend inwardly in the direction toward one another. As shown, the members 150 and 152 are supported in spaced-apart relation by a weblike plate 154 which is suitably afiixed to the upright flanges 156 and 158 of the members 150 and 152, respectively, such as by welding or the like. The plate 154 is spaced apart from and extends generally parallel to the flanges 160 and 162 defining a slot 155 therebetween adapted to slidably receive the upper flange 118 of the support am 108. Preferably, the members 150 and 152 are spaced apart from one another so that the inner marginal ends 164 and 165 of the flanges 160 and 162 extend generally parallel with respect to one another defining a lengthwise extending slot 166 therebetween for slidably receiving the web portion 116 of the arm member 108 therein. In addition, by this arrangement, the flanges 160 and 162 provide bearing surfaces, as at 167, along which the upper flange 118 may slide when the scraper member 124 is moved transversely lengthwise along the arm member 108. A bearing plate 170 (Fig. 14) may also be provided adjacent the lower edge 172 of the lower slot 146 to provide a greater bearing surface, as at 174, on which the confronting lower surface 176 of the bottom flange 120 may slide. Preferably, the transverse distance between the lower surface 176 of the lower flange 120 and the under surface 178 of the upper flange 118 is slightly less than the transverse distance between the bearing surface 174 of the plate 170 and the bearing surfaces 167 of the members 150 and 152 to prevent binding of the scraper member 124 with the arm member 108 and to enable the scraper member 124 to move freely with respect thereto.

In the invention, a locking means 180 is provided to limit the rearward movement of each of the scraper members 122 and 124 with respect to the arm members 106 and 108, respectively, when the plow mechanism is in operation. In the form shown, the locking means 180 (Fig. 12) comprises a locking member 182, such as a pin or the like, having an enlarged head portion 184 (Fig. 14) thereon, which is adapted for detachable connection with a respective one of the arm members, such as 108, and which is adapted for abutting engagement with a respective one of the scraper members, such as 124. A plurality of apertures, as at 183, may be spaced lengthwise along the inwardly projecting portion of the upper flange 118 and adapted to receive the locking pin 182 therein. Preferably, the head 184 of the pin 182 projects outwardly from the flange 118 a distance greater than the transverse width of the slot 155 so that the head 184 will abuttingly engage the plate 154. The pin may be positioned rearwardly of the plate 154 for engagement with the rear edge of the plate to limit the rearward movement of the scraper member 124 when the excavating machine is in operation. By this arrangement, the scraper member 124 may be shifted axially along the arm member 108 to position the leading end of the scraper member 124 adjacent the outer periphery of the digging wheel, which position will vary depending upon the depth of the excavation. That is, the point of engagement of the digging wheel with the ground will shift forwardly and clockwise along the periphery of the digging wheel requiring periodic adjustment of the plow subassembly with respect to the support drum as thedepth of the excavation is increased. In addition, the pin 182 may also be positioned in a respective one of the apertures 183 forwardly of the plate 154 for engagement with the forward edge 192 thereof of limit forward movement of the'scraper member 124 along the arm member 108 when the plow assembly is lifted to the inoperative or storage position to prevent the same from sliding forwardly toward the chassis of the excavating machine.

Referring again to Fig. 1, a support member 194 may be provided to support the plow assembly 41 in the inoperative position or raised position, as at 115. Preferably, the support member includes a chain 196 which may be attached at the upper end to the boom 35. The other end of the chain may be provided with a hook 198 which is adapted for interlocking engagement with the scraper member, and in the preferred form, is interlocked with a handle 200 (Fig. 12) which is mounted on the plate 130. Only one chain is necessary, but one chain may be provided for each scraper member.

We claim: I

1. An excavating machine including a chassis and an endless digging unit mounted on the chassis for digging movement in a generally vertical plane for excavation of hard materials, comprising a wheellike digging member being of a solid, high-inertia construction and defined by opposed side surfaces,

a plurality of tooth members mounted on said digging member adjacent the outer periphery thereof, at least one set of bracketlike support members mounted in staggered relation on said digging member including a front face with each of said tooth members being detachably connected to a respective one of said support members adjacent said front face,

said front faces extending in generally parallel relation with respect to the direction of digging movement of said digging member, said front faces including a leading end and a trailing end and said tooth members including directing surfaces extending angularly outwardly from said front faces in a direction from said trailing end to said leading end, said tooth members being disposed in oppositely facing pairs, I 1

including one pair disposed generally centrally with respect to the opposed side surfaces of said digging member having their directing surfaces facing one another to provide a narrow cut,

another pair arranged with their directing surfaces facing oppositely from said one pair and being spaced outwardly therefrom in a direction toward said opposite side surfaces of said digging member to provide an intermediate cut, and

at least one more pair arranged with their directing surfaces facing similarly to said one pair and spaced outwardly from said another pair and being disposed adjacent said opposed side surfaces of said digging member to provide a wide cut upon digging movement of said digging member.

2. An excavating machine according to claim 1, wherein the digging member has a moment of inertia of at least approximately 50,000 pound-feet squared.

3. An excavating machine according to claim 2, wherein the digging member is rotatably driven by the power source at a rotational speed of approximately 19 revolutions per minute.

4. An excavating machine according to claim 1, wherein the digging member comprises an inner ring and an outer ring, the

outer ring being of a solid, unitary construction.

5. An excavating machine according; to claim 1, wherein the 7. An excavating machine according to claim 6, wherein the digging unit includes bracketlike support members mounted on the digging member with each of the tooth members being attached to a respective one of the support members, and wherein each of said support members has its opposed ends divergently inclined with respect to each other in the direction of angular offset of the material-directing surface so as to permit reversible mounting of the support members on the digging member so that either end of the support member may be forwardly disposed in the direction of digging movement while permitting the material-directing surface to be angularly offset to either side of the vertical plane of digging rotation and while permitting the material-directing surface and the general plane of the forward end of its associated support member, to be angularly otfset to the same side of the vertical plane of digging rotation so that excavated spoil is moved in the same direction by the tooth member and] its associated support member.

8. An excavating machine according to claim 6, wherein said at least one set of tooth members comprises a plurality of at least three pairs of tooth members which are sequentially and circumferentially spaced from each other with respect to the direction of digging movement, the material-directing surfaces of the first pair disposed to face toward the vertical plane of digging rotation, the material-directing surfaces of the second pair disposed to face away from the vertical plane of digging rotation, and the material-directing surfaces of the third pair disposed to face toward the vertical plane of digging rotation.

9. An excavating machine according to claim 3, wherein adjacent of the tooth members are disposed in laterally offset relation with respect to each other and with respect to the vertical plane of digging rotation.

10. An excavating machine according to claim 4, wherein the support members include a base portion and an upright portion which extends angularly away from said base portion, the opposed ends of the upright portion being inclined with respect to each other in a direction perpendicular to the vertical plane of digging rotation for reversible mounting on the digging member and for providing cutting edges adjacent the opposed ends.

11. An excavating machine according to claim 10, wherein the opposed ends are inclined toward one another in a direction parallel to the vertical plane of digging rotation.

12. An excavating machine according to claim 10, wherein the base portion extends transversely from one side of and generally perpendicularly with respect to the upright por tion, and wherein the opposed ends are inclined convergently with respect to each other in a direction away from the base portion. 

1. An excavating machine including a chassis and an endless digging unit mounted on the chassis for digging movement in a generally vertical plane for excavation of hard materials, comprising a wheellike digging member being of a solid, high-inertia construction and defined by opposed side surfaces, a plurality of tooth members mounted on said digging member adjacent the outer periphery thereof, at least one set of bracketlike support members mounted in staggered relation on said digging member including a front face with each of said tooth members being detachably connected to a respective one of said support members adjacent said front face, said front faces extending in generally parallel relation with respect to the direction of digging movement of said digging member, said front faces including a leading end and a trailing end and said tooth members including directing surfaces extending angularly outwardly from said front faces in a direction from said trailing end to said leading end, said tooth members being disposed in oppositely facing pairs, including one pair disposed generally centrally with respect to the opposed side surfaces of said digging member having their directing surfaces facing one another to provide a narrow cut, another pair arranged with their directing surfaces facing oppositely from said one pair and being spaced outwardly therefrom in a direction toward said opposite side surfaces of said digging member to provide an intermediate cut, and at least one more pair arranged with their directing surfaces facing similarly to said one pair and spaced outwardly from said another pair and being disposed adjacent said opposed side surfaces of said digging member to provide a wide cut upon digging movement of said digging member.
 2. An excavating machine according to claim 1, wherein the digging member has a moment of inertia of at least approximately 50,000 pound-feet squared.
 3. An excavating machine according to claim 2, wherein the digging member is rotatably driven by the power source at a rotational speed of approximately 19 revolutions per minute.
 4. An excavating machine according to claim 1, wherein the digging member comprises an inner ring and an outer ring, the outer ring being of a solid, unitary construction.
 5. An excavating machine according to claim 1, wherein the digging member is mounted for rotation in a vertical plane of digging rotation, the plane being centrally disposed with respect to the lateral periphery of the digging member.
 6. An excavating machine according to claim 5, wherein the tooth members include a material-directing surface which is angularly disposed iN offset relation with respect to the vertical plane of digging rotation for moving excavated material forwardly with respect to the direction of digging movement and upwardly with respect to the bottom of the excavation formed by the digging member.
 7. An excavating machine according to claim 6, wherein the digging unit includes bracketlike support members mounted on the digging member with each of the tooth members being attached to a respective one of the support members, and wherein each of said support members has its opposed ends divergently inclined with respect to each other in the direction of angular offset of the material-directing surface so as to permit reversible mounting of the support members on the digging member so that either end of the support member may be forwardly disposed in the direction of digging movement while permitting the material-directing surface to be angularly offset to either side of the vertical plane of digging rotation and while permitting the material-directing surface and the general plane of the forward end of its associated support member to be angularly offset to the same side of the vertical plane of digging rotation so that excavated spoil is moved in the same direction by the tooth member and its associated support member.
 8. An excavating machine according to claim 6, wherein said at least one set of tooth members comprises a plurality of at least three pairs of tooth members which are sequentially and circumferentially spaced from each other with respect to the direction of digging movement, the material-directing surfaces of the first pair disposed to face toward the vertical plane of digging rotation, the material-directing surfaces of the second pair disposed to face away from the vertical plane of digging rotation, and the material-directing surfaces of the third pair disposed to face toward the vertical plane of digging rotation.
 9. An excavating machine according to claim 3, wherein adjacent of the tooth members are disposed in laterally offset relation with respect to each other and with respect to the vertical plane of digging rotation.
 10. An excavating machine according to claim 4, wherein the support members include a base portion and an upright portion which extends angularly away from said base portion, the opposed ends of the upright portion being inclined with respect to each other in a direction perpendicular to the vertical plane of digging rotation for reversible mounting on the digging member and for providing cutting edges adjacent the opposed ends.
 11. An excavating machine according to claim 10, wherein the opposed ends are inclined toward one another in a direction parallel to the vertical plane of digging rotation.
 12. An excavating machine according to claim 10, wherein the base portion extends transversely from one side of and generally perpendicularly with respect to the upright portion, and wherein the opposed ends are inclined convergently with respect to each other in a direction away from the base portion. 